Investigation and modeling of the avalanche effect in MOSFETs with non-uniform finger spacing

This paper investigates the effect of a non-uniform gate-finger spacing layout structure on the avalanche breakdown performance of RF CMOS technology.Compared with a standard multi-finger device with uniform gate-finger spacing,a device with non-uniform gate-finger spacing represents an improvement of 8.5%for the drain-source breakdown voltage(BV_ds) and of 20%for the thermally-related drain conductance.A novel compact model is proposed to accurately predict the variation of B V_ds with the total area of devices,which is dependent on the different finger spacing sizes.The model is verified and validated by the excellent match between the measured and simulated avalanche breakdown characteristics for a set of uniform and non-uniform gate-finger spacing arranged nMOSFETs.     

Chromium Oxide Reduction from Slag by Silicon and Magnesium

Experimental and theoretical studies were performed in order to estimate the effect of the basicity of the slag as well as the amount of reducing agents on the reduction of chromium oxide from a slag in contact with molten steel at 1600 °C. The aim of this work was to compare the efficiency of magnesium and silicon as reducing agents of Cr₂O₃. The slag system contained CaO, MgO, SiO₂, CaF₂ and Cr₂O₃ together with Fe‐alloys (Fe‐Si or Fe‐Si‐Mg). The maximum Cr yield was about 81% with Fe‐44%Si‐9%Mg and 88% with Fe‐75%Si. That means that the reducing effect of Mg was much better than that of Si. Some experiments were conducted to study the effect of initial Cr in steel on the chromium oxide reduction reaction. Three initial Cr contents were tested (0.15, 2 and 4 mass%). It was found that chrome was partially bound into stable spinel phase MgO·Cr₂O₃ in the final slag. Thermodynamic estimations were made to determine the effect of process temperature, slag basicity and the amount of reducing agents in the slag on the Cr recovery. The efficiency of Cr reducing agents increased in the order: Si, Al, Ca and Mg. The Cr yield increased with slag basicity and amount of reducing agents.     

Some mechanistic aspects of a nickel-catalyzed electrochemical cross-coupling between aryl halides and substituted chloropyridazines

The nickel-2,2′-bipyridine catalyzed electrochemical cross-coupling reaction between an aryl halide and a chloropyridazine was investigated by an electrochemical study. The electrochemical behavior of the divalent nickel complex is affected by the presence of pyridazine rings which act as co-ligands of nickel. Cyclic voltammetry indicates that the cross-coupling reaction involves first a rapid oxidative addition of the chloropyridazine on the electrogenerated zerovalent nickel complex. The coupling product is then obtained by reaction with the aryl halide.     

Investigation of urea oxidation as a potential anode reaction during CO2 electrolysis

Journal of Applied Electrochemistry - The electrooxidation of urea was investigated on Ni90Fe10 electrodeposited films as an alternative reaction to the oxygen evolution reaction (OER) during CO2...     

Glycerylbisether sulfates. I: Improved synthesis

Sparse literature outlines previous syntheses for glycerylbisether sulfates, which, while giving rise to the desired molecules, are somewhat cumbersome and suffer from undersired by-product formation. We now report an improved synthesis of the title compounds that results in greater simplicity and reduced by-product formation. An hypothesis is advanced to explain the by-product formation.     

Driven interval shift dynamics in sigma-delta modulators and phase-locked loops

In this paper, we show how consideration of the first-order sigma-delta (/spl Sigma//spl Delta/) modulator with sampled periodic input motivates study of the maps known mathematically as driven interval shifts. We derive new results concerning the behavior of these maps, and apply these results to provide new insight into the behavior of /spl Sigma//spl Delta/ modulators and phase-locked loops. We will see that viewing these systems through the mechanism of the driven interval shift allows us to identify common features in their behavior.     

Anomalies as a catalyst for middle school students' knowledge construction and scientific reasoning during science inquiry.

Knowledge construction and scientific reasoning of 7th-grade students were examined during a 3-week inquiry unit in genetics, in which anomalies were used as a catalyst for student learning. Students used genetics simulation software to develop hypotheses and run tests of fruit fly crosses in order to develop mental models of simple dominance trait transmission. Instruction was intended to support discovery of anomalous patterns and development of explanations. Qualitative and quantitative analyses indicated that student explanations showed a significant shift toward greater explanatory power of the anomalous inheritance patterns. However, this shift did not occur evenly. Students were more likely to propose hypotheses and explanations for the more frequently occurring anomaly and more likely to run the test that produced that outcome relative to the less frequently occurring anomaly. (PsycINFO Database Record (c) 2010 APA, all rights reserved)